A French court has convicted the ex-managers of breast implant maker PIP of fraud and sentenced the company's founder to four years in jail.

The now-defunct firm, Poly Implant Prothese (PIP), was at the centre of worldwide concern two years ago after it was revealed to have used industrial-grade silicone in thousands of breast implants sold worldwide.

The court sentenced PIP founder Jean-Claude Mas to four years in prison, imposed a 75,000 euro ($113,000) fine and banned him permanently from working in medical services or running a company.

Mas, a 74-year-old dubbed "the sorcerer's apprentice of implants" by prosecutors, did not react as the verdict was read out in court.

Four other former PIP executives were also convicted by the court in Marseille and given lesser sentences.

The scandal first emerged in 2010 after doctors noticed abnormally high rupture rates in PIP implants.

It gathered steam worldwide in 2011, with some 300,000 women in 65 countries believed to have received the faulty implants.

During a month-long trial in Marseille in April, the defendants admitted to using the industrial-grade silicone but Mas, who spent eight months in pre-trial detention, denied the company's implants posed any health risks.

More than 7,500 women have reported ruptures in the implants and in France alone 15,000 have had the PIP implants replaced.

But health officials in various countries have said they are not toxic and do not increase the risk of breast cancer.

More than 7,000 women had declared themselves civil plaintiffs in the case and several dozen were in court on Tuesday for the verdict.

The court also sentenced PIP's former general manager Claude Couty to three years in prison, with two years suspended.

Quality control director Hannelore Font and production director Loic Gossart were both sentenced to two years in prison, with one suspended, and research director Thierry Brinon was given an 18-month suspended sentence.

Mas, a one-time travelling salesman who got his start in the medical business by selling pharmaceuticals, founded PIP in 1991 to take advantage of the booming market for cosmetic implants.

He built the company into the third-largest global supplier of implants, but came under the spotlight when plastic surgeons began reporting an unusual number of ruptures in his products.

Health authorities later discovered he was saving millions of euros by using industrial-grade gel in 75 per cent of the implants.

PIP's implants were banned and the company eventually liquidated.

PIP had exported more than 80 per cent of its implants, with about half going to Latin America, about a third to other countries in western Europe, about 10 per cent to eastern Europe and the rest to the Middle East and Asia.